Electricity from a Nernst Filament. 243 
(diagram 4) and neighbouring curves show three distinct 
stages. In the first stage the current increases rapidly with 
Diagram 5. 
go 
75x 10-9 ampere. 
Current 1 
300 400. 
Volts. 
the potential. As the potential is increased further the rate 
of increase of the leak diminishes. In the second stage the 
current increases only very slowly for a considerable range 
R2 
